Built-In Coil Current Sensing for 7-Tesla H/Na and H/P Magnetic Resonance Imaging

Abstract

This article introduces two designs for dual-tuned built-in radio-frequency coil current sensing in 7-Tesla magnetic resonance imaging based on the current forcing property of the quarter-wave transmission line. The first design offers dual-tuned built-in coil current sensing at 1H/23Na resonant frequencies to probe the coil current consecutively at 298 MHz and 78.8 MHz, without the need for any integrated sensor on the coil. The second design enables dual-tuned built-in coil current sensing at 1H/31P resonant frequencies to probe the coil current at 298 MHz and 120 MHz consecutively. The first design achieved good matching (<−40 dB) and low insertion loss (<0.5 dB) for 1H and 23Na magnetic resonance signals. The 1H/31P design also exhibited good matching (<−30 dB) and low insertion loss (<0.67 dB). Therefore, both designs show promising potential for monitoring current flows in dual-tuned coils at the Larmor frequencies of different atomic nuclei.

Keywords

• current sensing
• dual-tuned
• magnetic resonance imaging
• power amplifier
• radio frequency